Generator regulating device



Patented Mayv 14, 1935 omaaroa aaoum'rmo DEVICE Bennett M. Iieece.Cleveland, and Dale 8. Cole, Cleveland Heights, Ohio, asslgnors to TheLeece-Nevllle Company, Cleveland, Ohio, a

corporation of Ohio Application November 28, 1931, Serial No. 577,836

3 Claims.

- This invention relates to generating systems of the type provided onvehicles for lighting, battery charging, and other purposes, and moreparticularly to an improved form of regulating device for such a system.

An object of the present invention is to provide an improved form ofregulator of the vibratory contact type wherein destructive sparking atthe contacts is reduced to a minimum.

Another object of the invention is to provide an electromagnet having acore element disposed in an air-tight envelope and a make and breakdevice associated with said core.

A further object of the invention is to provide a regulating devicehaving a coil disposed around an air-tight envelope, and a core for thecoil, which is positioned in the envelope andiincludes a vibratorymember.

Other objects and advantages of the invention will be apparent from thefollowing description when taken in conjunction with the accompanyingsheet of drawing, wherein Fig. 1 is a diagrammatic view representing agenerating system embodying the regulating means of our invention.

Fig. 2 is a sectional view, of somewhat diagrammatic form, representinganother regulating device constructed according to our invention.

Fig. 3 is a similar sectional view taken through another regulatingdevice of our invention, and

Fig. 4 is a transverse sectional view taken substantially on line 4-4 ofFig. 1.

Detailed reference will now be made to the accompanying drawing, whereinwe have illustrated the regulating device 01 our invention as embodiedin a generating system of the type commonly provided on motor vehiclesfor auxiliarypurposes. The invention is not to be regarded, however, asbeing limited to this particular use, 'nor to the specific arrangementsillustrated in the drawing.

Our regulating device, as herein disclosed, represents an improvementover the regulating device of the Leece Patent No. 1,540,698, dated June2, 1925, and over the regulating device disclosed in our applicationSerial No. 572,042, iiled October 30, 1931.

Our improved regulating device is especially useful in connection with agenerating system of the type provided on motor vehicles, such as thatillustrated in Fig. l of the drawing, comprising a generator III havingmain brushes II and II for supplying current to the load conductors l3and I4, and a shunt iield l5 adapted to be energized from a third brushit disposed between the main brushes H and I2. The current supplied tothe load conductors l3 and 44 by the main brushes may be utilized forany desired purpose, such as lighting, battery charging and other uses.

The regulating device itself comprises an electromagnet having coils orwindings l1 and I8, which are disposed around an air-tight envelope I 8containing a make and break device, and which are adapted to beenergized from the generator in. These coils are in additive relationand function in the manner described in detail in the patent referred toabove.

For the purpose of disclosing the present invention it is pointed outbriefly that the coil I1 is a shunt coil having its ends permanentlyconnected to the main brushes II and I2 by means oi! the conductors 20and 2|, and the coil I8 is an operating coil having its ends connectedto the main brushes II and 12 in such a manner that its circuit may beailected or altered by the make and break device within the envelope i9.As explained more fully in the patent referred to above, the operatingcoll l8, upon being energized by the generator Ill, actuates the makeand break device within the envelope, while the shunt coil II,responding to changes in the voltage output 01' the generator, controlsor regulates the rate of operation or the make and break device.

The envelope, about which the coils of the electromagnet are arranged,may be of any appropriate construction, such as a tube of glass, or anyother suitable non-magnetic material, which is evacuated andhermetically sealed. The make and break device disposed within thisenvelope comprises stationary and movable core members 22 and 23, ofmagnetic material, and a pair of cooperating contact elements 24 and 25.The core element 22 and the contact element 24 are 'held substantiallyimmovably within the envelope, preferably by supporting conductors 26and 21 which extend through, and are sealed in, the end walls of theenvelope. The contact element 25 is movable toward and away from thestationary contact 24, and is carried by the movable core element 23.This movable core element is preferably so shaped that it conforms tothe cross sectional shape of the envelope, and will be guided during itsmovement by engagement with the inner surface of theenvelope wall. Ifdesired the sides of the movable core members may be depressed orundercut, as indicated at 24' so as to reduce the friction between thismember and the wall of the envelope when the device is operated in ahorizontal position. As shown in Fig. 1 of the drawing,

this movable core member may be of substantially U-shape, having atransverse bottom wall portion 28 forming a seat for one end of the coilspring 29. This coil spring is disposed between the'movable core memberand the stationary core member 22 for the purpose of nor mally urgingthe contact element 25 toward the contact element 24. If desired thestationary core member 22 may be provided with a spring centeringprojection of suitable shape, such as the projection 30 illustrated inthe drawing.

Regulation of the voltage of the generator I is obtained, in thisinstance, by controlling the excitation of the shunt field I5. Variationin the excitation of the shunt field is obtained by providing aresistance unit 3|, of suitable value, which is adapted to beintermittently connected into and short-circuited from the field circuitby the contact elements 24 and 25. To this end the resistance 3| isshown in Fig. l as being arra .iged in parallel with the contactelements 24 and 25 with its terminals connected to the conductors 26 and21 by means of the conductors 32 and 33. The conductor 26 is connectedwith the main brush H by conductor 34, while the conductor 21 isconnected to one end of the winding |8 by means of conductors 35 and 36,and to one end of the shunt field |5 by means of the conductor 31. Thusthe circuit for the coil l8 may be traced from main brush throughconductor 34, and then through core members 22 and 23 and spring 29 tocontact element 25. Whenever the contact element is moved intoengagement with the contact element 24, the circuit for the coil |8 iscompleted through conductors and 36, the coil itself, and throughconductor 2| to main brush l2.

From the circuit arrangement as just described, it will be seen that asthe speed of the generator increases, the strength of the magneticfield, produced by the coils I! and I8, is increased with the resultthat the movable core element 23 is attracted toward the stationary coreelement 22 thereby separating the contact elements 24 and 25. Separationof these contact elements interrupts the passage of current through theenvelope so that all of the exciting current for the shunt field l3 mustpass through the resistance 3|. With the resistance 3| connected inseries with the field winding, in this manner, the ampere turns of thelatter are materially reduced and consequently the voltage of thegenerator tends to drop. The decreasing generator voltage causes acorresponding decrease in the magnetization of the coils IT and |8, thusallowing the spring 29 to move the core member 23 away from the coremember 22. This separating movement of the core members brings thecontact element 25 into engagement with contact element 24, therebyestablishing a current path through the envelope and short-circuitingthe resistance 3| out of the field circuit. The removal of thisresistance from the field circuit results in the field strength beingincreased and the magnetization of the coils H and I8 being againincreased correspondingly. The increase in the strength of the magneticfield produced by the coils I1 and I8, again causes the core member 23to be moved and the contact elements 24 and 25 to be opened, and theresistance member 3| again out into the field circuit. It will beunderstood, of course, that during the operation of the device themovement or vibration of the core member 23 takes place very rapidly andthe resistance 3| is cut into, and

short-circuited from, the field circuit at a corresponding rate. Theelectromagnet consisting of the coils l1 and I8, and the make and breakdevice contained in the envelope, thus responding to the voltage of thegenerator, control the excitation of the generator field to therebymaintain the generated voltage at a substantially constant value.

In Fig. 2 of the drawing, we have shown a regulator wherein thearrangement of the core elements is somewhat different from thatillustrated in Fig. 1. In this arrangement the core, which is providedfor the coils and 4| surrounding the envelope 42, comprises a stationarymember 43 of magnetic material and a movable member 44. This movablemember is in the form of a disc comprising a comparatively small body ofmagnetic material, and carries a movable contact element 45. A coilspring 45 disposed between the core members tends to separate thelatter, thereby urging the contact element 45 toward a stationarycontact element 46.

In making the movable core member in the form of a disc comprising arelatively small mass of magnetic material, as shown in this figure, theeffect of gravity and external vibration upon this member will be almostnegligible. comparative lightness of this movable core member increasesthe efliciency of the operation of the device when the same is set at anangle other than vertical, by tending to reduce the friction betweenthis member and the walls of the envelope.

In Fig. 3 of the drawing, we have shown still another arrangementwherein the electromagnet is provided with an external magnetic core 5|,which is so disposed relative to the air-tight envelope 52 as to cause astrong magnetic circuit through the stationary and movable core members53 and 54 contained within the envelope. In this arrangement thestationary core member 53 is made relatively long so as to provide amagnetic path within the envelope which will have very littlereluctance. The movable core member 54 may be in the form of arelatively light disc of magnetic material which is urged away from thestationary core member by a coil spring 55. A contact element 56 carriedby the movable core member cooperates with a stationary contact element51 under the infiuence of the spring and under the influence of themagnetic field produced by the winding.

In the regulator constructions, which we have illustrated and described,the air-tight envelopes may be evacuated to such an extent that theycontain an atmosphere of very low pressure, after which they arepermanently sealed, or they may be evacuated and then charged with aninert gas, such as nitrogen, to provide the same with an atmospherehaving desired characteristics. During the operation of a regulatingdevice of this kind, the inert gas, contained within the envelope, orthe rarefied air contained therein, as the case may be, tends to preventoxidation of the contact elements when sparking occurs, with the resultthat the useful life of these elements is materially prolonged.Moreover, in the arrangement which we have provided, the air-tightenclosing envelope protects the contact elements against moisture,foreign material, and the meddling of unexperienced persons. Thisenvelope also renders the operation of the device less subject tointerference by external shocks or vibrations.

It will be understood, of course, that in the regulating devicesillustrated and described, the

Likewise the A coiled spring, which is disposed between the coremembers, is formed of current conducting material so as to complete thepath through the core members and contact elements arranged within theenvelope. For most eillcient operation our regulating devices arepreferably arranged with the axis of the envelope in a verticalposition, but this is not essential and if desired the devices may bemounted and operated with the envelope extending in an inclined or ahorizontal position. Although we have shown our regulating meansembodied in a generating system of the threebrush type, obviously thesame can be used as well in a generating system wherein the tenninals oithe shunt field are connected to the main brushes.

While we have illustrated and described our invention in a detailedmanner,it should be understood that we do not intend to limit ourselvesto the precise details of construction and arrangements of partsillustrated and described, but regard our invention as including suchchanges and modifications as do not involve a departure from the spiritof the invention and the scope of the appended claims.

Having thus described our invention, we claim:

1. In a vibratory electromagnetic device of the character described thecombination of an airtight envelope, a magnet coil disposed around saidenvelope, 2. contact in said envelope, a core for said coil stationarilysupported in said envelope, and a vibratory member in said enveloperesponsive to changes in the magnetization of said core and normallybiased toward engagement with said contact for vibratory cooperationwith the latter.

2. In a vibratory electromagnetic device of the character described thecombination of an airtight envelope, a magnet coil disposed around saidenvelope, a contact in said envelope, a core for said coil stationarilysupported in said envelope, a vibratory member in said envelope betweensaid core and said contact responsive to changes in the magnetization ofsaid core, and a spring interposed between said core and said vibratorymember for biasing the latter toward said contact, said springestablishing an electrical connection between said vibratory member andthe core.

3. In a vibratory electromagnetic device of the character described thecombination of an elongated air-tight tubular envelope of non-magneticmaterial, a magnet coil disposed around said envelope, an elongated corefor said coil stationarily supported in said envelope, a vibratorymember axially movable in said envelope in response to magnetization ofsaid core by said coil, cooperating contacts in said envelope, one ofsaid contacts being relatively stationary and the other being carried bythe vibratory member, and a spring electrically connecting saidvibratory member and said core and normally biasing the vibratory memberin a direction to close said contacts.

BENNE'I'I M. LEECE. DALE S. COLE.

